1. Field of the Invention
The present invention relates to a recording medium recording and reproducing apparatus and, more particularly, to a recording medium recording and reproducing apparatus in which a head is moved adjacent to a recording medium in association with conveyance of the recording medium by a recording medium conveying mechanism.
2. Description of the Related Art
An electronic apparatus such as a personal computer or a word processor is provided with a magnetic disc apparatus as means for recording information. In a magnetic disc apparatus, when a disc cartridge is attached, a magnetic disc in the disc cartridge is rotated so as to perform a magnetic recording or reproducing operation by a magnetic head being made contact with the magnetic disc.
Additionally, the above-mentioned magnetic disc apparatus is provided with a recording medium conveying mechanism that comprises a disc holder into which the disc cartridge is inserted and a slider which slides by an inserting operation of the disc cartridge so as to move the disc holder from a cartridge insertion/eject position to a cartridge loading position.
The slider is urged by a coil spring in one direction. When the disc cartridge is inserted, a latch lever is pressed by an end of the disc cartridge and an engagement of the slider by the latch lever is released. Thereby, the slider moves in an urging direction so that the disc holder is moved to the cartridge loading position. At this time, the disc holder moves downwardly from the cartridge insertion/eject position to the cartridge loading position, and, thereby, the disc in the disc cartridge is loaded on a turntable.
Additionally, when the disc cartridge is ejected, an eject button provided on a front bezel is pressed so that the slider moves in an ejecting direction which causes the disc holder to move upwardly from the cartridge loading position to the cartridge insertion/eject position. At the same time, the engagement of the latch lever by the slider is released, and, thereby, the latch lever rotates while pressing the disc cartridge in the ejecting direction. As mentioned above, the disc cartridge loaded in the magnetic disc apparatus is mechanically ejected when the eject button is pressed.
However, in the above-mentioned magnetic disc apparatus, when the eject button is pressed, the disc cartridge is ejected irrespective of an operational mode of the magnetic disc apparatus. Accordingly, if the eject button is pressed while the disc cartridge is loaded and a magnetic recording or reproducing operation is being performed by a magnetic head, there is a problem in that the slider is moved in the ejecting direction and the disc holder is moved upwardly from the cartridge loading position to the cartridge insertion/eject position and, thus, the disc cartridge is ejected.
Thus, for example, there may be a case in which a disc cartridge is forcibly ejected while information is being magnetically recorded on the magnetic which causes termination of the recording operation before whole information to be recorded is completely recorded on the magnetic disc. In this case, if a power of the magnetic disc apparatus is turned off, the information to be recorded on the magnetic disc may be lost.
Additionally, in the above-mentioned apparatus, the spring urging the slider is set to generate a strong force so as to positively perform the loading operation of the disc holder. Accordingly, the slider is accelerated by the strong spring force from an initial time of insertion of the cartridge to the cartridge is loaded. Thus, a speed of the magnetic disc is excessively increased when the slider reaches an end of travel at which the speed of the slider is constant. Thus, there is a problem in that a shock of the magnetic head when contacting the magnetic disc is too strong so that the magnetic head damages a magnetic film on the magnetic disc.
In order to eliminate such a problem, the conventional apparatus is provided with a damper to reduce a speed of movement of the slider. As for such kind of damper, an oil damper may be used. The oil damper comprises a gear engaging with a rack provided to the slider, a rotating member rotating with the gear and a case in which grease is filled and the rotating member is accommodated. When the rotating member provided in the case of the oil damper is rotated due to a movement of the slider provided in the case, an attenuating force is generated by the grease filled in the case. As a result, the speed of movement of the slider is reduced.
However, in the above-mentioned magnetic disc apparatus, since viscosity of the grease filled in the oil damper depends on a temperature, a resistance of the grease may be excessively increased at a low temperature, and the magnetic disc may not be loaded reliably. On the other hand, since the resistance of the grease is decreased at a high temperature, a power of the loading operation is increased which may damage the magnetic film of the magnetic disc.
Additionally, in the recent magnetic disc apparatus, recording density is increased by increasing a rotational speed of the disc so as to increase a recording capacity of the magnetic disc. In such a magnetic disc apparatus achieving a large recording capacity, a floating force is exerted on a magnetic head due to an air flow generated in association with a high-speed rotation of the magnetic disc, and, thereby, a magnetic recording and reproducing operation can be performed while the magnetic head is slightly separated from the magnetic head so that the magnetic head does not damage the surface of the magnetic disc.
In the above-mentioned apparatus, when the magnetic head is made contact with the magnetic disc when a rotational speed of the magnetic disc is low, a floating force is not generated in the magnetic head. Thus, there is a high possibility that the magnetic head contacts the magnetic disc and the magnetic film formed on the magnetic disc is damaged.